Mobile Access Router and Mesh Networks
Design Guide
The Cisco 3200 Series Mobile Access router (also referred to as the MAR3200 or the mobile access
router (MAR)) is a compact, high-performance access solution that offers seamless mobility and
interoperability across wireless networks. This guide describes how to use the MAR3200 in mesh
networks for communicating mission-critical voice, video, and data.
Contents
Introduction 2
MAR3200 Interfaces 2
MAR3200 WMIC Features 5
Universal Workgroup Bridge Considerations
MAR3200 Management Options 7
6
Using the MAR with a Cisco 1500 Mesh AP Network
Vehicle Network Example 8
Simple Universal Bridge Client Data Path 8
7
Configuration Examples 10
Connect to the Cisco 3200 Series Router 10
Configure the IP Address, DHCP, and VLAN on the MAR
WMIC Configurations 11
WMIC Universal Bridge Client Configuration 11
WMIC Bridge Configuration 11
Configuring the WMIC to Serve as an Access Point
Security 13
Authentication Types 13
Open Authentication to the WMIC
10
12
13
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Copyright © 2004 Cisco Systems, Inc. All rights reserved.
Contents
Shared Key Authentication to the WMIC 14
EAP Authentication to the Network 14
MAC Address Authentication to the Network 16
Key Management 17
Using CCKM Key Management 17
Using WPA Key Management 17
Security Configuration 17
Assigning Authentication Types to an SSID 18
Configuring Authentication Types for 2.4 WMIC Radios 19
EAP-TLS Authentication with AES Encryption Example 21
Configuring the Root Device Interaction with WDS 22
Configuring Additional WPA Settings 22
WPA and Pre-Shared Key Configuration Example 23
Matching Authentication Types on Root and Non-Root Bridges 23
Using the MAR3200 in Mobile Environments 24
WMIC Roaming Algorithm 24
Using Network Address Translation (NAT) with the MAR3200 25
MAR3200 in Mobile IP Environments 26
The MAR 3200 Mobile IP Registration Process 26
Mobile IP Configuration 28
Basic HA and Foreign Agent Router Configurations 28
Configuring OSPF Routing Between HA, FA1, and FA2 28
Configuring IP Address, DHCP, and VLAN on the MR 29
Configuring a 2.4GHz Access Point on the MR 29
Configuring the 2.4 Universal Work Group Bridge Client 30
Configuring the Home Agent (HA) 31
Configuring the Foreign Agent (FA) 32
Configuring the Mobile Router (MR) 33
Verifying the Mobile IP Configuration 33
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Introduction
Introduction
The size of the Cisco MAR3200 (see Figure 1) makes it ideal for use in vehicles in public safety,
homeland security, and transportation sectors. The MAR3200 delivers seamless mobility across multiple
radio, cellular, satellite, and wireless LAN (WLAN) networks, and can communicate mission-critical
voice, video, and data across peer-to-peer, hierarchical, or meshed networks.
Figure 1
Cisco 3200 Series Mobile Access Router
MAR3200 Interfaces
The MAR3200 can be configured with multiple Ethernet and serial interfaces, and up to three radios.
The router itself is made up of stackable modules referred to as cards. Figure 2 shows the stackable card
configuration. The MAR3200 has two 2.4GHz Wireless Mobile Interface Cards (WMICs) one 4.9GHz
WMIC, one Fast Ethernet Switch Mobile Interface Card (FESMIC) and one Mobile Access Router Card
(MARC)). The MR can also be configured in a rugged enclosure with power adapters.
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Introduction
Figure 2
Card Connections
WMIC1
Universal Work Group Bridge
WMIC2
Vehicle Device WLAN
SMIC
Connection to Cellular
WAN Modem
FESMIC
Connection to Client
Laptop
190901
MARC
For more information on MAR3200 configuration options, refer to the following URL:
http://www.cisco.com/en/US/prod/collateral/routers/ps272/product_data_sheet0900aecd800fe973.html
Figure 3 provides an example of a MAR3200 configured with two WMICs, an FESMIC, and a MARC.
Figure 3
Mobile Unit Configuration Example
The following tables list the port-to-interface relationships and hardware types. Refer to these tables for
configurations where you need to plug other devices into the MAR3200.
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Introduction
Table 1 shows the setup of WMICs on the Cisco 3230 Mobile Access router.
Table 1
WMIC Ports
Internal Wiring Ports
Radio Type
WMIC 1 (W1)
FastEthernet 0/0
2.4GHz
WMIC 2 (W2)
FastEthernet 2/3
2.4GHz
WMIC 3 (W3)
FastEthernet 2/2
4.9GHz
Table 2 shows the setup of serial interfaces on the Cisco 3230 Mobile Access router.
Table 2
SMIC Ports
Internal Wiring Ports
Interface Type
Serial 0
Serial 1/0
DSCC4 Serial
Serial 1
Serial 1/1
DSCC4 Serial
Internal
Serial 1/2
DSCC4 Serial
Internal
Serial 1/3
DSCC4 Serial
Table 3 shows the setup of Fast Ethernet interfaces on the Cisco 3230 Mobile Access router.
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Introduction
Table 3
Fast Ethernet Ports
Internal Wiring Ports
Interface Type
Internal WMIC 1 Fast Ethernet 0/0
Fast Ethernet
FE0X
Fast Ethernet 2/0
Fast Ethernet
FE1X
Fast Ethernet 2/1
Fast Ethernet
Internal WMIC 3 Fast Ethernet 2/2
Fast Ethernet
Internal WMIC 2 Fast Ethernet 2/3
Fast Ethernet
MAR3200 WMIC Features
Table 4 highlights the software features of WMICs running Cisco IOS.
Table 4
WMIC IOS Software Features
Feature
Description
VLANs
Allows dot1Q VLAN trunking on both wireless and Ethernet interfaces. Up
to 32 VLANs can be supported per system.
QoS
Use this feature to support quality of service for prioritizing traffic on the
wireless interface. The WMIC supports required elements of Wi-Fi
Multimedia (WMM) for QoS, which improves the user experience for audio,
video, and voice applications over a Wi-Fi wireless connection and is a
subset of the IEEE 802.11e QoS specification. WMM supports QoS
prioritized media access through the Enhanced Distributed Channel Access
(EDCA) method.
Multiple BSSIDs
Supports up to 8 BSSIDs in access point mode.
RADIUS accounting
When running the WMIC in access point (AP) mode you can enable
accounting on the WMIC to send accounting data about authenticated
wireless client devices to a RADIUS server on your network.
TACACS+
administrator
authentication
TACACS+ for server-based, detailed accounting information and flexible
administrative control over authentication and authorization processes. It
provides secure, centralized validation of administrators attempting to gain
access to your WMIC.
Enhanced security
Supports three advanced security features:
Enhanced
authentication services
•
WEP keys: Message Integrity Check (MIC) and WEP key hashing CKIP
•
WPA
•
WPA2
Allows non-root bridges or workgroup bridges to authenticate to the network
like other wireless client devices.
After a network username and password for the non-root bridge or
workgroup bridge are set, (LEAP), EAP-TLS or EAP-FAST can be used for
authentication in dynamic WEP, WPA, or WPA2 configurations.
802.1x supplicant
In AP mode, the Mobile Access Router supports standard 802.1x EAP types
for WLAN clients.
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Introduction
Table 4
WMIC IOS Software Features (continued)
Fast secure roaming
Fast, secure roaming using Cisco Centralized Key Management (CCKM) in
Work Group Bridge mode and Universal Work Group Bridge mode.
Universal workgroup
bridge
Supports interoperability with non-Cisco APs.
Repeater mode
Allows the access point to act as a wireless repeater to extend the coverage
area of the wireless network.
Universal Workgroup Bridge Considerations
The Cisco Compatible eXtensions (CCX) program delivers advanced WLAN system level capabilities
and Cisco-specific WLAN innovations to third party Wi-Fi-enabled laptops, WLAN adapter cards,
PDAs, WI-FI phones, and application specific devices (ASDs). The 2.4 GHz WMIC provides CCX client
support. When the 2.4 GHz WMIC is configured as a universal workgroup bridge client, it does not
identify itself as a CCX client. However, it does support CCX features. Table 5 lists the supported
features.
Table 5
CCX Version Feature Support
Feature
v1
v2
v3
v4
AP
WGB
WGB
Client
X
X
X
X
X
X
X
X
X
X
X
Security
Wi-Fi Protected Access (WPA)
IEEE 802.11i - WPA2
WEP
X
X
X
X
X
X
X
IEEE 802.1X
X
X
X
X
X
X
X
LEAP
X
X
X
X
X
X
X
X
X
X
X
X
X
X
EAP-FAST
CKIP (encryption)
X
Wi-Fi Protected Access (WPA):
802.1X + WPA TKIP
X
X
X
X
X
X
With LEAP
X
X
X
X
X
X
With EAP-FAST
X
X
X
X
X
IEEE 802.11i- WPA2:
802.1X+AE
X
X
X
X
X
With LEAP
X
X
X
X
X
With EAP-FAST
X
X
X
X
X
CCKM EAP-TLS
X
X
X
X
EAP-FAST
X
X
X
X
Mobility
AP-assisted roaming
X
X
X
X
X
X
Fast re-authentication via
CCKM, with LEAP
X
X
X
X
X
X
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Using the MAR with a Cisco 1500 Mesh AP Network
Table 5
CCX Version Feature Support (continued)
Fast re-authentication via
CCKM with EAP-FAST
X
X
X
X
X
MBSSID
X
X
Keep-Alive
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
QoS and VLANs
Interoperability with APs that
support multiple SSIDs and
VLANs
X
X
Wi-Fi Multimedia (WMM)
Performance and Management
AP-specified maximum
transmit power
Recognition of proxy ARP
information element (For ASP)
X
Client Utility Standardization
Link test
MAR3200 Management Options
You can use the WMIC management system through the following interfaces:
•
The IOS command-line interface (CLI), which you use through a PC running terminal emulation
software or a Telnet/SSH session.
•
Simple Network Management Protocol (SNMP).
•
Web GUI management.
Using the MAR with a Cisco 1500 Mesh AP Network
The Universal Workgroup Bridge feature for the Cisco MAR3200 WMIC allows the WMIC radio to
associate to non-Aironet based access points. It also supports a majority of CCXv4 client features. In the
version 4.0 software release for the Cisco Wireless LAN Controller (WLC), and Mesh APs,
enhancements have been added to support Cisco 1230, 1240, 1130, or 3200 products associating to the
Cisco 1500 as a workgroup bridge (WGB). These two feature updates allow the MAR to act as a client
to the 1500 Mesh AP networks or Light Weight Access Point Protocol (LWAPP) WLAN networks
enabling new solutions for public safety, commercial transportation, and defense markets. The MAR not
only has Fast Ethernet and Serial interface connections for other client devices, but can also use them to
connect to other network devices for backhaul purposes.
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Using the MAR with a Cisco 1500 Mesh AP Network
Vehicle Network Example
This section describes a simple application for the MAR3200 in a Mesh network using its universal
workgroup bridge feature to connect to the Mesh WLAN. Figure 4 illustrates this example.
•
A Cisco 3200 Series router installed in a mobile unit allows the client devices in and around the
vehicle to stay connected while the vehicle is roaming.
•
WMICs in vehicle-mounted Cisco 3200 Series routers are configured as access points to provide
connectivity for 802.11b/g and 4.9-GHz wireless clients.
•
Ethernet interfaces are used to connect any in-vehicle wired clients, such as a laptop, camera, or
telematics devices, to the network.
•
Another WMIC is configured as a Universal Workgroup Bridge for connectivity to a Mesh AP,
allowing transparent association and authentication through a root device in the architecture as the
vehicle moves about.
•
Serial interfaces provide connectivity to wireless WAN modems that connect to cellular networks
such as CDMA or GPRS. The Wireless 802.11 connections are treated as preferred services because
they offer the most bandwidth. However, when a WLAN connection is not available, cellular
technology provides a backup link. Connection priority can be set by routing priority, or by the
priority for Mobile IP.
Figure 4
Vehicle Network Example
Mesh Network
190902
8 0 2.1 1
Simple Universal Bridge Client Data Path
The IP devices connected to the MAR are not aware that they are part of a mobile network. When they
must communicate with another node in the network, their traffic is sent to their default gateway, the
Cisco 3200 Series router. The Cisco 3200 Series router forwards the traffic to the Mesh APs WLAN, the
mesh AP then encapsulates the data packets in LWAPP and forwards them through the network to the
controller.
As shown in Figure 5, the Cisco 3200 Series router sends traffic over the Universal Bridge Client WLAN
backhaul link. This traffic then crosses the WLAN to the controller where it is then forwarded out the
controller interface to the wired network. Return traffic destined for any client attached to the MAR
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Using the MAR with a Cisco 1500 Mesh AP Network
would be forwarded via a static route pointing back to the controller of the Mesh network. Figure 6
shows the return path to the MAR. Mobile IP eliminates the need for static routing and is covered later
in this document. NAT can be used in simple deployments when Mobile IP is not available.
The data path example shown in Figure 5, and previously described, represents the traffic in a pure
Layer 2 Mesh when the MAR is using only the WMIC for backhaul. If the deployment calls for more
complexity (such as secondary cellular backhaul links) then Mobile IP is required.
When the WMIC is used as a Universal Bridge Client, it sets up its wireless connections the same way
any wireless client does.
Figure 5
Client
Simple Layer 2 Data Path Example
WLC
RAP
MAP
190903
8 0 2.1 1
MAR
Client
Client Return Data Path
WLC
RAP
MAP
8 0 2.1 1
MAR
190904
Figure 6
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Configuration Examples
Configuration Examples
This section provides configuration examples for the Cisco 3200 Series router.
Connect to the Cisco 3200 Series Router
Attach the console cable to both the serial port of your PC and the Mobile Access router console port
(DB9 socket). Use a straight-through DB9-to-DB9 cable.
Configure the IP Address, DHCP, and VLAN on the MAR
Step 1
Connect to and log in to the MAR. Create a loopback interface and assign an IP address:
bridge(config)# int loopback 0
bridge(config-if)# ip address 24.24.24.24 255.255.255.255
Step 2
To create VLAN 2 in the VLAN database, enter:
bridge# vlan database
Step 3
Configure the VLAN 3 and VLAN 2 interfaces. VLAN 3 is used for the 2.4 GHz WMIC2 (W2) which
is acting as AP and VLAN 2 is used for the 4.9GHz WMIC (W3). Configure FA2/0, FA2/1 and FA2/3
to be in VLAN 3, and FA 2/2 to be in VLAN 2.
Step 4
Create VLAN 4 in the VLAN database for connection between WMIC 1 and the MARC.
Step 5
Connected to
Interface
Radio Type
VLAN
Description
PC
FastEthernet2/0
None
3
Fast Ethernet link for end device
WMIC 1 (W1) FastEthernet0/0
2.4GHz
4
2.4 GHz Universal Work Group Bridge
connection to Mesh Network
WMIC 2 (W2) FastEthernet2/3
2.4GHz
3
Provide 2.4 GHz AP Hotspot around the
mobile router
WMIC 3 (W3) FastEthernet2/2
4.9GHz
2
4.9GHz uplink as Workgroup Bridge
Configure the DHCP server for VLAN 3 using following commands:
bridge(config)# ip dhcp pool mypool
bridge(dhcp-config)# network 10.40.10.0 /28
bridge(dhcp-config)# default-router 10.40.10.1
bridge(config)# ip dhcp excluded-address 10.40.10.1 10.40.10.3
Step 6
Verify that the wired client on VLAN 3 has been assigned a DHCP IP address in the 10.40.10.0/28
subnet.
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Configuration Examples
WMIC Configurations
This section provides information on the various WMIC configurations.
WMIC Universal Bridge Client Configuration
The WMIC can be configured as a universal workgroup bridge. In this role, the WMIC has the following
functionality:
•
Associates to the IOS and non-IOS access points.
•
Interoperability—A universal workgroup bridge can forward routing traffic using a non-Cisco root
device as a universal client. The universal workgroup bridge appears as a normal wireless client to
the root device. As a root device, the WMIC supports Cisco-compatible extension clients, with all
CCXv3 features and many CCXv4 features.
To configure the WMIC as a Universal Workgroup Bridge, enter the following command:
bridge(config)# station-role workgroup-bridge universal [mac address]
Note
You must use the mac-address of the associated VLAN that the WMIC is bridged to. As an example, we
will use the mac-address of VLAN 1. To acquire the MAC address of VLAN 1, console in to the MARs
router card and enter the show mac-address-table command.
WMIC Bridge Configuration
The WMIC can be configured as a bridge. There are three install modes: automatic, root, and non-root:
•
Automatic mode activates the bridge install and alignment mode, and specifies that the device
automatically determines the network role. If the device is able to associate to another Cisco root
device within 60 seconds, it assumes a non-root bridge role; otherwise it assumes a root device role.
The device can be configured into root device or non-root bridge modes to avoid the 60-second
automatic detection phase.
•
Root mode specifies that the device is operating as a root device and connects directly to the main
Ethernet LAN network. In this mode, the unit accepts associations from other Cisco bridges and
wireless client devices.
•
Non-root mode specifies that the device is operating as a non-root bridge, and that it connects to a
remote LAN network, and that it must associate with a Cisco root device by using the wireless
interface. Bride mode is the only mode that supports the distance command.
The distance command specifies the distance from a root device to its clients (non-root bridges
and/or workgroup bridges). The distance setting adjusts the time out values to account for the time
required for radio signals for radio signals to travel from a root device to its clients (non-root bridges
and/or workgroup bridges). In installation mode, the default distance setting a 2.4-GHz WMIC is 99
km for maximum delay spread during antenna alignment. In other modes, the default distance
setting is 0 km. Changing to a different mode sets the distance to the default distance. If more than
one non-root bridge (or workgroup bridge) communicates with the root device, enter the distance
from the root device to the non-root bridge (or work-group bridge) that is farthest away. Enter a
value from 0 to 99 km for a 2.4-GHz WMIC or 0 to 3 km for a 4.9-GHz WMIC. You do not need to
adjust this setting on non-root bridges.
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Configuration Examples
To configure the WMIC to determine is role automatically, perform the following steps:
Step 1
To enter global configuration mode, enter:
bridge# configure terminal
Step 2
To enter configuration mode for the radio interface, enter:
bridge(config)# interface dot11radio port
Step 3
To configure the WMICs bridge role, enter the following commands:
bridge(config-if)# station-role {root [bridge |
bridge(config-if)# non-root workgroup-bridge install [automatic | root | non-root]}
The station-role command specifies that role of the WMIC is chosen based on the device to which it is
associated.
Set the WMIC role:
Step 4
•
To specify that MAR3200 WMIC operates as the root bridge device, use the station-role root
bridge command. This mode does not support wireless client associations.
•
To specify that the MAR3200 WMIC operates in workgroup bridge mode, use the station-role
workgroup-bridge command. As a workgroup bridge, the device associates to an Aironet access
point or bridge as a client and provides a wireless LAN connection for devices connected to its
Ethernet port.
Enter a distance setting from 0 to 99 km for a 2.4-GHz WMIC or 0 to 3 km for a 4.9-GHz WMIC:
bridge(config-if)# distance kilometers
Step 5
Use the mobile station command to configure a non-root bridge or workgroup bridge as a mobile
station. When this feature is enabled, the bridge scans for a new parent association when it encounters a
poor Received Signal Strength Indicator (RSSI), excessive radio interference, or a high frame-loss
percentage. Using these criteria, the WMIC searches for a new root association and roams to a new root
device before it loses its current association. When the mobile station setting is disabled (the default
setting) the WMIC does not search for a new association until it loses its current association.
Step 6
Enter the end command to complete the configuration.
Step 7
To make a backup copy of the configuration, enter:
bridge# copy running-config startup-config
Configuring the WMIC to Serve as an Access Point
The WMIC can be configured as a root access point. In this role, it accepts associations from wireless
clients. This can be a useful configuration if you are planning to deploy a mobile hotspot.
To configure the WMIC as an access point, perform the following steps:
Step 1
To enter global configuration mode, enter:
bridge# configure terminal
Step 2
To specify the interface configuration mode for the radio interface, enter:
bridge(config)# interface dot11radio port
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Step 3
To specify the SSID the AP will use, enter:
bridge(config-if)# ssid given ssid
Step 4
To specify the authentication type to be used, enter:
bridge(config-if)# authentication open
Step 5
To specify the radio channel the AP will operate on, enter:
bridge(config-if)# channel 11
Step 6
To specify for the WMIC to function as a root access point, enter:
bridge(config-if)# station-role root access-point
Step 7
Enter the end command to complete the configuration.
Step 8
To make a backup copy of the configuration, enter:
bridge# copy running-config startup-config
Security
This section describes the security features of the WMIC.
Authentication Types
This section describes the authentication types that you can configure on the WMIC. The authentication
types are tied to the SSID that you configure on the WMIC. Before wireless devices can communicate,
they must authenticate to each other using open, 802.1x/EAP based or shared-key authentication. For
maximum security, wireless devices should also authenticate to your network using EAP authentication,
an authentication type that relies on the presence of an authentication server on your network.
The WMIC uses four authentication mechanisms or types and can use more than one at the same time.
These sections explain each authentication type:
•
Open Authentication to the WMIC, page 14
•
Shared Key Authentication to the WMIC, page 15
•
EAP Authentication to the Network, page 15
•
MAC Address Authentication to the Network, page 17
Open Authentication to the WMIC
Open authentication allows any wireless device to authenticate and then attempt to communicate with
another wireless device. Open authentication does not rely on a RADIUS server on your network.
Figure 7 shows the authentication sequence between a non-root bridge and a root device using open
authentication. In this example, the non-root bridge's WEP key does not match the bridge's key, so it can
authenticate but it cannot pass data.
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Security
Figure 7
Open Authentication
8 0 2.1 1
Switch on
LAN 1
Non-Root Bridge
with WEP key = 321
8 0 2.1 1
Non-Root Bridge
with WEP key = 123
Switch on
LAN 1
191187
1. Authentication request
1. Authentication response
Shared Key Authentication to the WMIC
Cisco provides shared key authentication to comply with the IEEE 802.11b and IEEE 802.11g standards.
However, because of shared key's security flaws, we recommend that you use another method of
authentication, such as EAP, in environments where security is an issue. During shared key
authentication, the root device sends an unencrypted challenge text string to the client device that is
attempting to communicate with the root device. The client device requesting authentication encrypts
the challenge text and sends it back to the root device
Both the unencrypted challenge and the encrypted challenge can be monitored, which leaves the root
device open to attack from an intruder who calculates the WEP key by comparing the unencrypted and
encrypted text strings. Figure 8 shows the authentication sequence between a device trying to
authenticate and a bridge using shared key authentication. In this example the device's WEP key matches
the bridge's key, so it can authenticate and communicate.
Figure 8
Sequence for Shared Key Authentication
8 0 2.1 1
Switch on
LAN 1
Non-Root Bridge
with WEP key = 123
8 0 2.1 1
Non-Root Bridge
with WEP key = 123
Switch on
LAN 1
1. Authentication request
3. Encrypted challenge response
191188
2. Unencrypted challenge
4. Authentication response
EAP Authentication to the Network
This authentication type provides the highest level of security for your wireless network. By using the
Extensible Authentication Protocol (EAP) to interact with an EAP-compatible RADIUS server, the root
device helps the authenticating device and the RADIUS server perform mutual authentication and derive
a dynamic session key, which is used by both the root and authenticating devices to further derive the
unicast key. The root generates the broadcast key and sends it to the authenticating device after
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Security
encrypting it with a unicast key. The unicast key is used to exchange unicast data between the root device
and authenticated device, and the broadcast key is used to exchange multicast and broadcast data
between them.
When you enable EAP on your bridges, authentication to the network occurs in the sequence shown in
Figure 9.
Figure 9
EAP Authentication
8 0 2.1 1
Switch on
LAN 1
8 0 2.1 1
Non-Root Bridge
with WEP key = 123
Non-Root Bridge
with WEP key = 123
Switch on
LAN 1
1. Authentication request
3. User name
(Relay to server)
(Relay to non-root bridge)
4. Authentication challenge
5. Authentication response
(Relay to server)
(Relay to non-root bridge)
6. Authentication success
7. Authentication challenge
(Relay to server)
(Relay to non-root bridge)
8. Authentication response
9. Authentication success
9. (Relay to server)
191189
2. Identity request
In Steps 1 through 9 in Figure 9, a non-root bridge and a RADIUS server on the wired LAN use 802.1x
and EAP to perform a mutual authentication through the root device:
•
The RADIUS server sends an authentication challenge to the non-root bridge.
•
The non-root bridge uses a one-way encryption of the user-supplied password to generate a response
to the challenge and sends that response to the RADIUS server.
•
Using information from its user database, the RADIUS server creates its own response and compares
that to the response from the non-root bridge.
•
When the RADIUS server authenticates the non-root bridge, the process repeats in reverse, and the
non-root bridge authenticates the RADIUS server.
•
When mutual authentication is complete, the RADIUS server and the non-root bridge determine a
session key that is unique to this session between the RADIUS server and non-root bridge and
provide the non-root bridge with the appropriate level of network access.
•
The RADIUS server encrypts and transmits the session key over the wired LAN to the root device.
•
The root device and the non-root bridge derive the unicast key from the session key. The root device
generates the broadcast key and sends it to the non-root bridge after encrypting it with the unicast
key.
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•
The non-root bridge uses the unicast key to decrypt the broadcast key. The non-root bridge and the
root device activate WEP and use the unicast and broadcast WEP keys for all communications
during the remainder of the session.
There is more than one type of EAP authentication, but the bridge behaves the same way for each type.
It relays authentication messages from the wireless client device to the RADIUS server and from the
RADIUS server to the wireless client device.
(If you use EAP authentication, you can optionally select open or shared key authentication, as well as
EAP authentication controls authentication both to your bridge and to your network.)
EAP-TLS
EAP-TLS uses public key infrastructure (PKI) to acquire and validate digital certificates. A digital
certificate is a cryptographically signed structure that guarantees the association between at least one
identifier and a public key. It is valid for a limited time period and use, subject to certificate policy
conditions. The Certificate Authority (CA) issues certificates to client and server. The supplicant and the
back-end RADIUS server must both support EAP-TLS authentication. The root device acts as an AAA
Client and is also known as the network access server (NAS). The root devices must support 802.1x/EAP
authentication process even though they are not aware of the EAP authentication protocol type. The NAS
tunnels the authentication messages between the peer (user machine trying to authenticate) and the AAA
server (such as the Cisco ACS). The NAS is aware of the EAP authentication process only when it starts
and ends.
EAP-FAST
EAP-FAST encrypts EAP transactions within a TLS tunnel. The TLS tunnel encryption helps prevent
dictionary attacks that are possible using LEAP. The EAP-FAST tunnel is established using shared secret
keys that are unique to users. Because handshakes that are based on shared secrets are intrinsically faster
than handshakes that are based on a PKI infrastructure, EAP-FAST is significantly faster than PEAP and
EAP-TLS.
EAP-FAST operates according to the following three phases:
•
Delivery of a key to the client
•
Establishment of a secure tunnel using the key
•
Authentication of the client over the secure tunnel
After successful client authentication to the EAP-FAST server, a RADIUS access-accept message is
passed to the root device (along with the master session key) and an EAP success message is generated
at the root device (as with other EAP authentication protocols). Upon receipt of the EAP-success packet,
the client derives a session key using an algorithm that is complimentary to the one used at the server to
generate the session key passed to the root device.
MAC Address Authentication to the Network
The access point relays the wireless client device's MAC address to a RADIUS server on the network,
and the server checks the address against a list of allowed MAC addresses. Because intruders can create
counterfeit MAC addresses, MAC-based authentication is less secure than EAP authentication.
However, MAC-based authentication does provide an alternate authentication method for client devices
that do not have EAP capability or can be used as a addition to EAP.
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Key Management
This section describes the available key management features.
Using CCKM Key Management
Using Cisco Centralized Key Management (CCKM), authenticated client devices can roam from one AP
to another without any perceptible delay during reauthentication. An LWAPP AP on the network
provides secure fast roaming, when the WLC creates a cache of security credentials for CCKM-enabled
devices on the subnet. The WLC cache of credentials dramatically reduces the time required for
reauthentication when a CCKM-enabled client device roams to an AP. When a client device roams and
tries to reauthentication to a new AP served by the same WLC or a WLC belonging to the same mobility
group, the WLC authenticates the client using its cache of client's credentials rather than requiring
RADIUS server to authenticate the client. The reassociation process is reduced to a two-packet exchange
between the roaming client device and the new AP. Roaming client devices reauthentication quickly
enough for there to be no perceptible delay in voice or other time-sensitive applications
Using WPA Key Management
Wi-Fi Protected Access (WPA) is a standards-based interoperable security enhancement that strongly
increases the level of data protection and access control for existing and future wireless LAN systems.
WPA is derived from the IEEE 802.11i standard. WPA leverages Temporal Key Integrity Protocol
(TKIP) or Advanced Encryption Standard (AES) for data protection.
WPA key management supports two mutually exclusive management types: WPA and WPA-Pre-Shared
key (WPA-PSK). Using WPA key management, the client device and the authentication server
authenticate with each other using the EAP authentication method, and the client device and server
generate a pairwise master key (PMK). Using WPA, the server generates the PMK dynamically and
passes it to the root device. With WPA-PSK, you configure a pre-shared key on both the client device
and the root device, and that pre-shared key is used as the PMK.
Note
Unicast and multicast cipher suites advertised in the WPA information element (and negotiated during
802.11 association) could potentially mismatch with the cipher suite supported in an explicitly assigned
VLAN. If the RADIUS server assigns a new VLAN ID which uses a different cipher suite from the
previously negotiated cipher suite, there is no way for the root device and the client device to switch back
to the new cipher suite. Currently, the WPA and CCKM protocols do not allow the cipher suite to be
changed after the initial 802.11 cipher negotiation phase. In this scenario, the non-root bridge is
disassociated from the wireless LAN.)
Security Configuration
The default configuration for the WMIC in AP mode has an SSID of autoinstall, which is also configured
as guest mode. In guest mode, the WMIC broadcasts this SSID in its beacon and allows client devices
with no SSID to associate.
Note
By default, the authentication type assigned to autoinstall is open. This enables clients with no security
settings to connect to the MAR3200. In order to secure the MAR, this configuration default must be
changed.
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Assigning Authentication Types to an SSID
From privileged EXEC mode, follow these steps to configure authentication types for SSIDs, such as an
AP, root bridge, or non-root bridge, on the root device:
Step 1
To enter global configuration mode for the router, enter:
bridge# configure terminal
Step 2
To create an SSID, enter:
bridge(config)# dot11 ssid ssid-string
The SSID can consist of up to 32 alphanumeric characters. SSIDs are case-sensitive.
Step 3
(Optional) To set the authentication type to “open” for this SSID, enter:
bridge(config-ssid)# authentication open [mac-address list-name [alternate]] [[optional]
eap list-name]
Open authentication allows any client device to authenticate and then attempt to communicate with the
WMIC.
Step 4
(Optional) Set the SSID's authentication type to open with MAC address authentication. The access point
forces all client devices to perform MAC-address authentication before they are allowed to join the
network. For list-name, specify the authentication method list. Use the alternate keyword to allow client
devices to join the network using either MAC or EAP authentication; clients that successfully complete
either authentication are allowed to join the network.
Step 5
(Optional) Set the SSID's authentication type to open with EAP authentication. The WMIC forces all
other client devices to perform EAP authentication before they are allowed to join the network. For
list-name, specify the authentication method list. Use the optional keyword to allow client devices using
either open or EAP authentication to associate and become authenticated. This setting is used mainly by
service providers that require special client accessibility.
Note
A root device configured for EAP authentication forces all client devices that associate to
perform EAP authentication. Client devices that do not use EAP cannot communicate with the
root device.
For more information on method lists, refer to the following URL:
http://www.cisco.com/en/US/docs/ios/12_2/security/configuration/guide/scfathen.html.
Step 6
(Optional) Use the following command to set the authentication type for the SSID to “shared key:”
bridge(config-ssid)# authentication shared [mac-address list-name] [eap list-name]
Note
Because of security flaws associated with using shared key, we recommend that you avoid using
it. You can assign shared key authentication to only one SSID.
Step 7
(Optional) Set the SSID's authentication type to shared key with MAC address authentication. For
list-name, specify the authentication method list.
Step 8
(Optional) Set the SSID's authentication type to shared key with EAP authentication. For list-name,
specify the authentication method list.
Step 9
(Optional) Set the authentication type for the SSID to use EAP for authentication and key distribution
by entering:
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bridge(config-ssid)# authentication network-eap list-name [mac-address list-name]
Step 10
(Optional) Set the SSID's authentication type to Network-EAP with MAC address authentication. All
client devices that associate to the access point are required to perform MAC-address authentication. For
list-name, specify the authentication method list.
Step 11
(Optional) Set the key-management type for the SSID to WPA, CCKM, or both:
bridge(config-ssid)# authentication key-management {[wpa] [cckm]} [optional]
If you use the optional keyword, client devices not configured for WPA or CCKM can use this SSID. If
you do not use the optional keyword, only WPA or CCKM client devices are allowed to use the SSID.
To enable CCKM for an SSID, you must also enable Network-EAP authentication. To enable WPA for
an SSID, you must also enable Open authentication or Network-EAP or both.
Note
Simultaneous use of WPA and CCKM is not supported with 802.11a radios.
Before you can enable CCKM or WPA, you must set the encryption mode to a cipher suite that
includes TKIP/AES-CCMP. To enable both CCKM and WPA, you must set the encryption mode
to a cipher suite that includes TKIP.
If you enable WPA for an SSID without a pre-shared key, the key management type is WPA. If
you enable WPA with a pre-shared key, the key management type is WPA-PSK.
To support CCKM, your root device must interact with the WDS device on your network.
Step 12
To return to privileged EXEC mode, enter:
bridge(config-ssid)# exit
Step 13
(Optional) To save your entries in the configuration file, enter:
bridge# copy running-config startup-config
Configuring Authentication Types for 2.4 WMIC Radios
To configure authentication types for SSIDs on the non-root side, in privileged EXEC mode, perform the
following steps:
Step 1
To enter global configuration mode, enter:
bridge# configure terminal
Step 2
To create the EAP profile, enter:
bridge(config)# eap profile profile-name-string
Step 3
To create a dot1x credentials profile and enter the dot1x credentials configuration submode, enter:
bridge(config)# dot1x credentials profile
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Step 4
To choose an EAP authentication method for authentication purposes, enter:
bridge(config-eap-profile)# method [fast|gtc|leap|md5|mschapv2|tls]
Step 5
Note
Step 6
Use the exit command to return to privileged EXEC mode.
A device configured for EAP authentication forces all root devices that associate to perform EAP
authentication. Root devices that do not use EAP cannot communicate with the device.
To enter global ssid mode, enter:
bridge(config)# dot11 ssid ssid-string
Step 7
(Optional) To set the authentication type for the SSID to “use EAP for authentication and key
distribution,” enter:
bridge(config-ssid)# authentication network-eap list-name
Step 8
To create a dot1x credentials profile and enter the dot1x credentials configuration submode, enter:
bridge(config)# dot1x credentials profile
Step 9
To specify the EAP profile, enter:
bridge(config-ssid)# dot1x eap profile profile-name-string
This is the profile you created in Step 2.
Step 10
(Optional) To set the key-management type for the SSID to WPA, CCKM, or both, enter:
bridge(config-ssid)# authentication key-management {[wpa] [cckm]} [optional]
If you use the optional keyword, client devices that are not configured for WPA or CCKM can use this
SSID. If you do not use the optional keyword, only WPA or CCKM client devices are allowed to use the
SSID. To enable CCKM for an SSID, you must also enable Network-EAP authentication. To enable
WPA for an SSID, you must also enable open authentication, network-EAP, or both.
Note
Only 802.11b and 802.11g radios support WPA and CCKM simultaneously.
Before you can enable CCKM or WPA, you must set the encryption mode to a cipher suite that includes
TKIP/AES-CCMP. To enable both CCKM and WPA, you must set the encryption mode to a cipher suite
that includes TKIP.
If you enable WPA for an SSID without a pre-shared key, the key management type is WPA. If you
enable WPA with a pre-shared key, the key management type is WPA-PSK.
Step 11
Enter the exit command and then, optionally, enter the copy running-config startup-config command
to create a copy of your configuration file.
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EAP-TLS Authentication with AES Encryption Example
Use the no form of the SSID commands to disable the SSID or to disable SSID features. The following
example sets the authentication type for the SSID bridgeman to open with EAP authentication. Bridges
using the SSID bridgeman attempt EAP authentication using the eap method name adam. This example
sets the authentication type for the SSID bridgeman to perform EAP-TLS authentication with AES
encryption. Bridges using this SSID attempt EAP authentication using a server ID named adam.
bridge# configure terminal
bridge(config)# dot11 ssid bridgeman
bridge(config-ssid)# authentication open eap eap_adam
bridge(config-ssid)# authentication network-eap eap_adam
bridge(config-ssid)# authentication key-management wpa
bridge(config-ssid)# infrastructure-ssid
bridge(config-ssid)# exit
bridge(config)# interface dot11radio 0
bridge(config-if)# encryption mode ciphers aes-ccm
bridge(config-if)# ssid bridgeman
bridge(config-if)# end
The configuration on workgroup bridges, non-root bridges, and repeater bridges associated to this bridge
would also contain these commands:
bridge# configure terminal
bridge(config)# eap profile authProfile
bridge(config-eap-profile)# method tls
bridge(config-eap-profile)# exit
bridge(config)# dot1x credentials authCredentials
bridge(config-dot1x-creden)# username adam
bridge(config-dot1x-creden)# password adam
bridge(config-dot1x-creden)# exit
bridge(config)# dot11 ssid bridgeman
bridge(config-ssid)# authentication open eap eap_adam
bridge(config-ssid)# authentication network-eap eap_adam
bridge(config-ssid)# authentication key-management wpa
bridge(config-ssid)# dot1x eap_profile authProfile
bridge(config-ssid)# dot1x credentials authCredentials
bridge(config-ssid)# infrastructure-ssid
bridge(config-ssid)# exit
bridge(config)# interface dot11radio 0
bridge(config-if)# encryption mode ciphers aes-ccm
bridge(config-if)# ssid bridgeman
bridge(config-if)# end
This example shows the RADIUS/AAA configuration on the root side for EAP authentication.
bridge# configure terminal
bridge(config)# aaa new-model
bridge(config)# aaa group server radius rad_eap
bridge(config-sg-radius)# server 13.1.1.99 auth-port 1645 acct-port 1646
bridge(config)# aaa authentication login eap_adam group rad_eap
bridge(config)# aaa session-id common
bridge(config)# radius-server host 13.1.1.99 auth-port 1645 acct-port 1646 key 7 141B1309
bridge(config)# radius-server authorization permit missing Service-Type
bridge(config)# ip radius source-interface BVI1
bridge(config)# end
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Configuring the Root Device Interaction with WDS
To support non-root bridges using CCKM, your root device must interact with the WDS device on your
network, and your authentication server must be configured with a username and password for the root
device. For more information on configuring WDS and CCKM on your wireless LAN, refer to Chapter
11 in the Cisco IOS Software Configuration Guide for Cisco Access Points at the following URL:
http://www.cisco.com/en/US/docs/wireless/access_point/12.4_10b_JA/configuration/guide/scg12410bchap4-first.html.
Step 1
On your root device, enter global configuration mode:
Router# configure terminal
Step 2
Configure a username and password for the AP to use for authentication.
You must configure the same username and password pair when you set up the root device as a client on
your authentication server:
bridge(configure)# wlccp ap username username password password
Configuring Additional WPA Settings
This section provides information on the addition settings that can be configured for WPA.
Setting a Pre-Shared Key
To support WPA on a wireless LAN where 802.1x-based authentication is not available, you must
configure a pre-shared key on the bridge. You can enter the pre-shared key as ASCII or hexadecimal
characters. If you enter the key as ASCII characters, you enter between eight and 63 characters, and the
bridge expands the key using the process described in the Password-based Cryptography Standard
(RFC2898). If you enter the key in hexadecimal characters, you must enter 64 hexadecimal characters.
Configuring Group Key Updates
In the last step in the WPA process, the root device distributes a group key to the authenticated non-root
bridge. You can use these optional settings to configure the root device to change and distribute the group
key based on association and disassociation of non-root bridges:
•
Membership termination—The root device generates and distributes a new group key when any
authenticated non-root bridge disassociates from the root device. This feature keeps the group key
private for associated bridges.
•
Capability change—The root device generates and distributes a dynamic group key when the last
non-key management (static WEP) non-root bridge disassociates, and it distributes the statically
configured WEP key when the first non-key management (static WEP) non-root bridge
authenticates. In WPA migration mode, this feature significantly improves the security of
key-management capable clients when there are no static WEP bridges associated to the root device.
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To configure a WPA pre-shared key and group key update options, in privileged EXEC mode, perform
the following steps:
Step 1
To enter global configuration mode, enter:
bridge# configure terminal
Step 2
To enter SSID configuration mode for the SSID, enter:
bridge(config)# dot11 ssid ssid-string
Step 3
To specify a pre-shared key for bridges using WPA that also use static WEP keys, enter:
bridge(config)# wpa-psk { hex | ascii } [ 0 | 7 ] encryption-key
Enter this key using either hexadecimal or ASCII characters. If you use hexadecimal, you must enter 64
hexadecimal characters to complete the 256-bit key. If you use ASCII, you must enter a minimum of
eight letters, numbers, or symbols, and the bridge expands the key for you. You can enter a maximum of
63 ASCII characters.
Step 4
Enter the end command to complete the configuration.
WPA and Pre-Shared Key Configuration Example
This example shows how to configure a pre-shared key for non-root bridges using WPA and static WEP,
with group key update options:
bridge# configure terminal
bridge(config)# dot11 ssid batman
bridge(config-ssid)# wpa-psk ascii batmobile65
bridge(config-ssid)# end
Matching Authentication Types on Root and Non-Root Bridges
To use the authentication types described in this section, the root device authentication settings must
match the settings on the non-root bridges that associate to the root device.
Table 6 lists the settings required for each authentication type on the root and non-root bridges.
Table 6
Client and Bridge Security Settings
Security Feature
Non-Root Bridge Setting
Static WEP with open Set up and enable WEP
authentication
Root Device Setting
Set up and enable WEP and enable
open authentication
Static WEP with
shared key
authentication
Set up and enable WEP and enable Set up and enable WEP and enable
shared key authentication
shared key authentication
LEAP authentication
Configure a LEAP username and
password
Set up and enable WEP and enable
network-EAP authentication
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Table 6
Client and Bridge Security Settings (continued)
CCKM key
management
Set up and enable WEP and enable Set up and enable WEP and enable
CCKM authentication
CCKM authentication, configure the
root device to interact with your WDS
device, and add the root device to your
authentication server as a client device
WPA key
management
Set up and enable WEP and enable Set up and enable WEP and enable
WPA authentication
WPA authentication
Using the MAR3200 in Mobile Environments
This section describes how the MAR is used in mobile environments.
WMIC Roaming Algorithm
There are four conditions that will trigger the WMIC to start scanning for a better root bridge or access
point:
•
The loss of eight consecutive beacons
•
A shift in the data rate
•
The maximum data retry count is exceeded (the default value is 64 on the WMIC)
•
A measured period of time of a drop in the signal strength threshold
Only the last two items in this list are configurable using the packet retries command and mobile
station period X threshold Y (in dBm); the remainder are hard-coded. These commands are issued
under the dot11 interface.
If a client starts scanning because of a loss of eight consecutive beacons, the message “Too many missed
beacons” is displayed on the console. In this case, the WMIC is acting as a Universal Bridge Client,
much like any other wireless client in its behavior.
An additional triggering mechanism, mobile station (if mobile station is configured), is not periodic but
does have two variables: period and threshold.
The mobile station algorithm evaluates two variables: data rate shift and signal strength and responds as
follows:
•
If the driver does a long term down shift in the transmit rate for packets to the parent, the WMIC
initiates a scan for a new parent (no more than once every configured period).
•
If the signal strength (threshold) drops below a configurable level, the WMIC scans for a new parent
(no more than once every configured period).
The data-rate shift can be displayed using the debug dot11 dot11Radio 0 trace print rates command.
However, this will not show the actual data rate shift algorithm in action, only the changes in data rate.
This determines the time period to scan, depending on how much the data rate was decreased.
The period should be set depending on the application. Default is 20 seconds. This delay period prevents
the WMIC from constantly scanning for a better parent if, for example, the threshold is below the
configured value.
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The threshold sets the level at which the algorithm is triggered to scan for a better parent. This threshold
should be set to noise+20dBm but not more than -70dBm (+70 because input for threshold is positive).
The default is -70 dBm.
Using Network Address Translation (NAT) with the MAR3200
Without the use of Mobile IP, devices connected to the MAR3200 will need to use NAT and static routing
to route traffic. On the MAR3200 create a subnet for clients to connect to and NAT that subnet to the
WMIC interface. For return traffic destined to devices or clients attached to the MAR3200 create static
route pointing back to the MARs WMIC interface on a router connecting to the mesh WLC.
To configure NAT and static routing, refer to Figure 10 and perform the following steps (assuming you
already configured the WMIC Universal Bridge Client and Mesh network).
Perform the following steps from the router’s global configuration mode:
Step 1
Create a VLAN for MAR connected clients:
MR(config)# int vlan 5
MR(config-if)# ip address 10.10.10.1 255.255.255.0
Step 2
Configure a DHCP pool to be used for connecting clients to the MAR:
MR(config)# ip dhcp pool CLIENTPOOL
MR(dhcp-config)# network 10.10.10.0 255.255.255.0
MR(dhcp-config)# default-router 10.10.10.1
MR(config)# ip dhcp excluded-address
MR(config)# ip dhcp excluded-address 10.10.10.1
Step 3
Using the following commands, configure NAT for that pool so that it uses the VLAN interface for the
WMIC that connects to the Mesh network:
MR(config)# ip nat inside source list 10 interface Vlan4 overload
!
MR(config)# access-list 10 permit 10.10.10.0 0.0.0.255 log
Step 4
Label your inside and outside NAT interfaces:
MR(config)# interface Vlan4
MR(config-if)# ip address 10.20.42.1 255.255.255.0
MR(config-if)# ip nat outside
!
MR(config)# interface Vlan5
MR(config-if)# ip address 10.10.10.1 255.255.255.0
MR(config-if)# ip nat inside
Step 5
Configure a default gateway on the MAR that points to the Mesh network:
MR(config)# ip default-gateway 10.20.41.1
Step 6
Save the configuration on the MAR3200 and exit:
MR# wr mem
MR# exit
Step 7
Log on to Router1 and configure static routing (see Figure 10 for static routes):
Router1(config)# ip route destination network netmask Forwarding router's address
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Step 8
Save your configuration and exit:
Router1# write memory
Router1# exit
Figure 10
NAT and Static Routing
Router1
IP Router 10.10.10.0 10.20.42.1 255.255.255.0
8 0 2.11
MAR
MAR3200
WMIC2 IP 10.20.42.1 255.255.255.0
NAT pool 10.10.10.2-254
191190
WLC1
WLAN1 10.20.41.1
MAR3200 in Mobile IP Environments
The wireless technologies used in many current metropolitan mobile networks include 802.11 wireless
mesh networks for general city-wide coverage, providing high speed access for bandwidth-intensive
applications, such as in-car video. For coverage areas where it is not practical to extend the wireless
mesh network, it can be supplemented by cellular services, such as CDMA 1x RTT. Using this approach,
cellular services can be used to fill gaps in connections and provide backup wireless connectivity. This
added backup interface requires Mobile IP to enable client roaming between the two separate networks.
To enable Mobile IP, an HA router must be added to the enterprise network to tunnel client traffic
between the MR and its home network. Another requirement for Mobile IP is to configure the MAR3200
as an MR. The following section describes Mobile IP registration process. Figure 11 shows a simple
Mobile IP (MIP) environment.
The MAR 3200 Mobile IP Registration Process
When the MAR3200 is associated to its Mesh network, the following events occur:
•
The MAR3200 goes through a Foreign Agent (FA) discovery process.
FAs advertise their existence periodically. If a MR does not hear a FA advertisement, it solicits itself
by sending a multicast advertisement to the address 224.0.0.2.
•
If an FA receives a solicitation from an MR, it responds with a unicast advertisement to the MR that
includes its Care of Address (CoA).
•
If the access network does not have a FA router, the MR can register itself with the HA by using a
Collocated Care of Address (CCoA).
The CCoA address is the IP address of the interface the MR uses to connect to the access network.
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•
The MR then sends in Registration Request (RRQ) to the HA.
•
The HA authenticates MR by sending a Registration reply (RRP) to the MR.
•
The HA provides a gratuitous APR update for the home network, then creates a GRE tunnel to the
FA if using Foreign Agent CoA (FACoA), or to the MR if you are using CCoA. It then adds a host
route to the MR.
•
Now, the MR has reached a registered state with the HA and the HA has set up a binding table entry
for the MR CoA. It will then tunnel and route traffic destined for the MR.
•
At this point, the MR is registered through a Mesh WLAN to its HA using the FACoA.
If any devices attached to the Cisco 3200 Series router must communicate with nodes on the home
network, they send the data to the Cisco 3200 Series router and Mobile IP tunnels the data to the
HA, with any traffic directed to MR clients tunneled from the HA to the MR. A simple Mobile IP
network with FACoA for Mesh and Collocated Care of Address (CCoA) for cellular is illustrated in
Figure 11.
Mobile IP is needed if your application requires routing to any devices or nodes attached to the
MAR3200.
•
If the MAR3200 is not in the vicinity of a wireless LAN hotspot it can use a backup wireless service
such as cellular modem to deliver the data.
In this case, the Cisco 3200 generates a CCoA from the IP address it acquired from the service
provider network and registers its CCoA with the HA. This CCoA address is the MR’s own interface
IP address it acquired via DHCP from the service provider. The registration process is similar to the
process for CoA registration.
Figure 11
Mobile IP Example
Internet
Corporate
Network
HA
FA
3G Network
RAP
MAP
8 0 2.1 1
190905
8 0 2.1 1
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Mobile IP Configuration
This section describes the Mobile IP configuration process.
Basic HA and Foreign Agent Router Configurations
This configuration illustrates connecting two separate Mesh networks that have different mobility groups
with Mobile IP. This enables an MR to seamlessly roam between the two networks (see Figure 11).
To configure an HA and FA router, perform the following steps:
Step 1
Log into the HA router. This can be any Cisco router that supports the Mobile IP feature set.
Step 2
Enable two Fast Ethernet or Gigabit Ethernet onboard interfaces which are used to connect to two foreign
agent routers:
HA1(config)# interface GigabitEthernet 0/1
HA1(config-if)# no shut
HA1(config)# Interface FastEthernet 0/1
HA1(config-if)# no shut
Step 3
Configure an IP address on each interface, based on the information in Figure 11:
HA1(config-if)# ip address network interface address netmask
Step 4
Configure a loopback interface:
HA1(config)# Interface loopback 0
HA1(config-if)# ip address network interface address netmask
Fast Ethernet interfaces on a switch module are for the devices behind HA. Default VLAN 1 is for the
home network.
Step 5
Log into the FA router, using the vlan database command in enable mode to create VLAN 2 and
VLAN 3. Create a VLAN interface for each VLAN using the IP address shown in Figure 11.
On the FA, VLAN 2 is used to connect to the HA router. VLAN 3 is for connection to the Mesh network.
Connected to
Interface
VLAN
Description
HA
FastEthernet2/0
2
Wired uplink connection to HA.
MESH AP
FastEthernet 0/0
3
Wired uplink connection to MESH AP
Configuring OSPF Routing Between HA, FA1, and FA2
To configure OSPF routing between the HA, FA1, and FA2, perform the following steps:
Step 1
Using the following commands, configure OSPF routing between the HA and FA routers. Use area 0
between routers and include all of the networks:
HA1(config)# router ospf 10
HA1(config-router)# network x.x.x.x y.y.y.y area 0
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Step 2
Use the show ip route command to verify the routing table on each router. From the FA, you should be
able to ping 10.10.10.1, which is the loopback address of the HA.
Configuring IP Address, DHCP, and VLAN on the MR
To configure the IP address, the DHCP, and the VLAN on the MR, perform the following steps:
Step 1
Connect to and log in to the MR.
Step 2
Create a loopback interface and assign IP address:
MR1(config)# Interface loopback 0
Step 3
Step 4
Create VLAN 2 in VLAN database using the vlan database command. Configure VLAN 1 and VLAN
2 interface. VLAN 1 is used for 2.4 GHz WMIC2 (W2) acting as AP and VLAN 2 is for 4.9GHz WMIC
(W3). Configure FA2/0, FA2/1 and FA2/3 to be in VLAN 1, and FA 2/2 to be in VLAN 2.
Connected to
Interface
Radio Type
VLAN
Description
PC
FastEthernet2/0
None
1
Fast Ethernet link for end device
WMIC 1 (W1) FastEthernet 0/0
2.4GHz
None
2.4 Ghz Wireless Universal Work Group
Bridge uplink to Mesh network
WMIC 2 (W2) FastEthernet 2/3
2.4GHz
1
Provide 2.4 GHz AP Hotspot around the
MR
Configure the wireless client’s DHCP pool:
MR1(config)# ip dhcp pool mypool
MR1(dhcp-config)# network 10.40.10.0 /28
MR1(dhcp-config)# default-router 10.40.10.1
MR1(dhcp-config)# ip dhcp excluded-address 10.40.10.1 10.40.10.3
Configuring a 2.4GHz Access Point on the MR
To configure a 2.4GHz access point on the MR, perform the following steps:
Step 1
Connect the console cable between the PC and the console port for 2.4GHz WMIC2 (W2) and log into
it using the default password.
Step 2
Configure the IP address on BVI interface and the default gateway. Verify the management connection
between WMIC and MARC:
MR1(config-if)# ip address network interface address netmask
MR1(config-if)# exit
MR1(config)# ip default-gateway address of default gateway
MR1(config)# exit
MR1# show ip interface brief
Step 3
Configure radio interface to have AP station role and SSID home pod#:
MR1(config)# interface Dot11Radio0
MR1(config-if)# ssid home pod#
MR1(config-if)# authentication open
MR1(config-if)# channel 6
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MR1(config-if)# station-role root ap-only
Authentication or static WEP key configuration is optional. Remove the default SSID and select a
non-overlapping channel that is different from the one selected in Step 2.
Configuring the 2.4 Universal Work Group Bridge Client
To configure the Universal Work Group Bridge Client, perform the following steps (from global
configuration mode):
Step 1
Connect the console cable between PC and the console port for 2.4GHz WMIC1 (W1) on FA1 and log
into it using default password.
Step 2
Configure the IP address on BVI interface and the default gateway based on diagram. Verify the
management connection between WMIC and MARC.
Step 3
Configure radio interface to have root station role and SSID metro pod#_bridge. Remove the default
SSID. Use open authentication and WPA share key:
MR1(config)# interface Dot11Radio0
MR1(config-if# encryption mode ciphers tkip
MR1(config-if# ssid MobileMESH
MR1(config-if# authentication open
MR1(config-if# authentication key-management wpa
MR1(config-if# infrastructure-ssid
MR1(config-if# wpa-psk ascii ciscocisco
MR1(config-if# station-role workgroup-bridge universal mac address
Note
Refer to Universal Workgroup Bridge Considerations, page 7 and WMIC Universal Bridge Client
Configuration, page 12 for more information regarding Universal Work Group Bridge and configuration
options.
Step 4
Connect to the WLAN controller and configure WLAN1 to use WPA-PSK with the same settings you
configured in Step 3.
Step 5
Verify the wireless connection between UWGB and MESH. Use the show dot1 association command
on the MR to verify the association status. Ping the WLC management interface address across the
wireless link.
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Configuring the Home Agent (HA)
The MR in the lab will host different IP networks. Use the entries in the following table to configure the
HA, FA, and MR.
Cisco 3200 Mobile Router
Mobile
Loopback
Router
Address
SPI Key Hex String
Mobile Networks
Mobile Router WMIC
FE 0/0 Address Workgroup
Bridge IP
Address
VLAN1 and PC IP
Address
SPI
1
10.20.10.1
100
1234567812345678
1234567812345678
10.30.10.0/28
10.40.10.0/28
10.30.10.1
10.30.10.2
10.40.10.1
10.40.10.0/28
2
10.20.10.2
200
2345678123456781
2345678123456781
10.30.10.16/28
10.40.10.16/28
10.30.10.17
10.30.10.18
10.40.10.17
10.40.10.16/28
Perform the following steps to configure the HA router:
Step 1
Log into the HA router. To determine the current configuration of the HA, enter either of these
commands:
HA# show ip mobile globals
HA# show running-configure
Step 2
Enable Mobile IP and configure the router as HA. Specify 10.20.10.0 as the virtual home network.
Step 3
to enter the Mobile IP mode, enter:
HA(config)# router mobile
Step 4
To specify that this is an HA, enter:
HA(config)# ip mobile home-agent
Step 5
To create the virtual network, enter:
HA(config)# ip mobile virtual-network 10.20.10.0
Step 6
255.255.255.0
Configure IP mobile-related parameters for IP mobile host, network and authentication. Refer to the
table for the variable information, such as the IP addresses and IP networks. Redistribute the mobile
routes into OSPF routing.
a.
To create the mobile host for the MR, enter:
HA(config)# ip mobile host mobile router loopback address from the table
virtual-network 10.20.10.0
255.255.255.0
b.
To specify networks on this MR, enter:
HA(config)# ip mobile mobile-networks mobile router loopback address from the table
c.
To configure the first network for this router, enter:
HA(config-router)# network mobile router network from the table 255.255.255.240
d.
To configure the second network for this router, enter:
HA(config-router)# network mobile router network from the table 255.255.255.240
e.
Enter:
HA(config)# ip mobile secure host mobile router loopback address spi SPI number from
table key hex string from table
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f.
To enter route protocol mode, enter:
HA(config)# router ospf 10
g.
Enter:
HA(config-router)# redistribute mobile subnets
Step 7
To verify your configuration, enter:
HA# show run
HA# show ip mobile globals
Note
The AAA server can be used to hold all MR spi and key. The command for this is ip mobile host mobile
router loopback address from table virtual-network 10.20.10.0 255.255.255.0 aaa load-sa. The
load-sa keyword instructs the HA to hold the security association (SPI/Key) in memory for subsequent
registrations. Additionally, you can enter a range of MR hosts in the command.
Networks on the MR can also dynamically register to the HA besides statically configuring networks
under ip mobile mobile networks. The command to do this on the HA is ip mobile mobile-network
mobile host register.
Configuring the Foreign Agent (FA)
The Foreign Agent does not need a specific configuration for each MR and its IP addresses. All that is
required is to activate the FA features on the router. The Mobile IP configurations are the same for two
FA routers. The following steps are required to enable the Mobile IP foreign agent service.
Step 1
Log into the FA router.
Step 2
Enter either of the following commands to determine the configuration on each FA router:
FA# show ip mobile globals
FA# show running-configure
Step 3
Enable MoIP on the FA router. Specify the VLAN 3 interface as care-of address. (COA), which is
connected to 4.9GHz bridge WMIC:
FA# router mobile
FA# ip mobile foreign-agent care-of vlan 3
Step 4
Enable IRDP and MoIP foreign-service on the VLAN 3 interface using following commands:
FA(config)# interface vlan 3
FA(config-if)# ip irdp
FA(config-if)# ip irdp minadvertinterval3
FA(config-if)# ip irdp maxadvertinterval 4
FA(config-if)# ip irdp holdtime 13must be > 3 X Max interval
FA(config-if)# ip mobile foreign-service
Step 5
To verify your configuration, enter:
FA# show run
FA# show ip mobile globals
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Configuring the Mobile Router (MR)
Perform the following steps to configure the MAR as a MR for use in a Mobile IP network:
Step 1
Log in to the MR.
Step 2
Enter either of the following commands to determine the current configuration of the MR:
MR# show ip mobile globals
MR# show running-configure
Step 3
Enable MoIP on the MR. Enable mobile route and configure the MoIP variable globally including HA
information. From the router’s global configuration mode, enter the following commands:
MR(config)# router mobile
MR(config)# ip mobile router
MR(mobile-router)# address mobile router loopback address 255.255.255.255
MR(mobile-router)# home-agent 10.10.10.1
Enter the exit command to exit from Mobile Router mode.
Enter:
MR(config)#ip mobile secure home-agent 10.10.10.1 spi SPI number from table key hex string
from table
Note
Step 4
The SPI number and string must match those you entered for the HA exactly or the tunnel and
the mobile connection will not come up.
Enable MoIP on MR. Enable mobile route and configure MoIP variable globally including HA
information:
MR(config)# interface vlan 2
MR(config-if)#ip mobile router-service roam
MR(config-if)#ip mobile router-service solicit interval 5
Step 5
Enter the show ip mobile router command to verify your configuration.
Verifying the Mobile IP Configuration
To verify the Mobile IP configuration, perform the following steps from the MR:
Step 1
To view the advertisements from the FAs, enter:
MR# debug ip icmp
Step 2
To verify that your MR is receiving advertisements from one FA, enter:
MR# show ip mobile router agent
Is your MR sending IRDP solicitations?
Step 3
To verify that the MR has associated with the HA, and that the tunnels are up, enter:
MR# show ip mobile router
Step 4
Log into that FA and examine the operation of the FA using the following commands:
FA# show ip mobile global
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FA# show ip mobile interface
FA# show ip mobile visitor
FA# show ip route
What do you see as the interface to the routes on the MR?
Step 5
Log into the MR and verify that the routes to the HA are there:
MR# show ip route
Step 6
To verify that traffic is being passed, enter:
MR# show ip mobile router traffic
Step 7
Enter:
MR# debug ip mobile router
Step 8
Enter the following command and monitor the output:
MR# clear ip mobile router registers
Step 9
Connect your laptop to the network behind the MR. You should also be able to ping the PCs behind the
HA router continuously.
Step 10
Log into the HA and examine its operation using the following commands:
HA#
HA#
HA#
HA#
HA#
show
show
show
show
show
ip
ip
ip
ip
ip
mobile
mobile
mobile
mobile
route
global
mobile-networks
host
secure host
For more information on Mobile IP, refer to the following URL:
http://www.cisco.com/en/US/tech/tk827/tk369/tk425/tsd_technology_support_sub-protocol_home.htm
l.
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